Electrical insulation



(No Model.)

f T. S. REED.

ELECTRICAL INSULATION.

No. 424,575. Patented Apr. l, 1890.-

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UNIT-En STATES PATENT OFFICE.

. THOMAS s. REED, oF JERsErorrY, NEW JERSEY;

i ELEo'rFuo/lu. I Nsu LATloN.

' SPECIFICATION forming pm of' meters Patent No. 424,575, dated Ap'rn 1, Iseo.

. Application mea'namm u, Isssfssrmuu. 292,714.; -mmaai To all whom it may concern:

Beit known that I, THOMAS S. REED, a citi- `zen of the United States, residing in Jerseyl City, Hudson county, New Jersey, have invented certain new anduseful Improvements in Electrical Insulation, of which the following is a specification.

This invention relates tothe insulation of electric wires, cables, or o ther electric conyielding cushion of peculiar character,'over which the insulating-layer of spun glass is applied, preferably by forming the spun glass into loosely-twisted strands or yarns and applying the same under-light tension around Vthe pad or cushion. Where a single layer only of insulation is to be applied, strands or yarns of spun glass are laid longitudinally around the conductor, and-are held in place thereagainst b y means of an outer layer of any material of suicient strength wound, braided, or otherwise applied in such manner as to bind said filaments against the conductor. In case two or more layers of insulating material are required, the first layer is applied, preferably, in the same mannernamely, by laying the filaments longitudinally on the. conductor or in any suitable mannerand a second layer of spun-glass filaments is appliedby winding a strand, yarn, or thread of spun glass spirally around the first layer.

In the case of circuit wires or leads which require to be of different colors in order to dis tinguish one from another I form the exterior layer of threads or strands of colored spun glass applied in any manner affording suflicient strength, such as by winding on, or braiding, or Weaving. Y

In the case of any part of the insulating- ,cover which is subjected to any considerable strain or wear, and preferably, also, 'in thc case of all portions of the insulating-covering wherein spun glass is employed, I make the strands-or yarns not of spun glass alone, but of filaments of spun glass combined with filaments or fibers of silk or other suitable textile fiber of animal or vegetable origin, thc combined filaments being loosely twisted or spun together.

In the accompanying drawings I have shown several different constructions embodying my invention.

Figure l is a dissected elevation, and Fig. 2 a transverse section, on a large scale, illustrating the preferred application of my'in- 'vention for the insulation of large conductors.

Fig. 3 is a similar dissected elevation, showing a modified construction. Fig. 4 is a dissected elevation, and Fig. 5a transverse section ..showing another application of my invention.

I will first describe the construction shown The conducting-wire here shown may be supposed to be a wire, or strand of Wires, or cable employed for conducting currents for electric lighting or for other purposes requiring thorough insulation. The wire A is first provided with a' cushion a by winding it with a layer of silk, wool, cotton, or other suitable fibrous material of sufficient softness, and which should be wound on loosely to render it soft and yielding. Over this cushion is laid a layer b of strands of lspun glass, which may be twisted threads or yarns, or the spun-glass fibers simply laid parallel against the exterior of the cushion. A second insulating-layer c is then applied by winding on a spiral spun-glass thread or yarn, one or more threads or yarns being used to make a layer of proper thickness. This layer confines the layer b tightly in place and closes its filaments together, so that a dense and prfu'ztically` impermeable covering is formed. Any number of layers b c may be applied, if desired, either in alternation or by the superposition of layers of either kind 011e upon another. In-the case of spirally-wound layers thus superposed thc successive layers should be Wound in opposite directions. A protective covering d is then applied by braiding or weaving threads or yarns of cotton,- wool, hemp, or other fiber tightly upon the outer layer of spun glass. .This protective covering maybe of any material and applied in any way heretofore known and practiced IOO in the art ofinsulating wires. For example, it may be a simple winding of coarse strong fibrous material or of fine wire. The protective covering may be painted over or varnished or coated with parafiine or other Wax, or with any protective or preservative substance desired.

Fig. 3 shows a wire A, which is insulated by a layer b of strands of spun glass laid against it longitudinally and wound and held securely in place upon it by a braided cover-` ing of. In this case the cushion a. is omitted.

Figs. fi and 5 show awire A, having a cushion a applied to it, over which is applied the insulation l in the form of a layer c of spun glass wound on spirally. If desired, it may be subsequently varnished or painted, rihe functionv of the cushion a is to make a somewhat yielding or elastic seat for the insulating layer or layers of spun glass, and is cspecially useful when the wire is subjected to considerable fiexure,as in the case of a flexible cable or an outdoor conductor strung upon poles or the like.

In any of the constructions shown the fibers of spun glass may be used 'alone for the insulating layer or layers 4or they maybe, mixed with fibers of organic textile material-such as silk, cotton, wool, &c.-if desired. For a woven or braided covering I consider it preferable to form the threads or yarns by spinning or twisting together filaments of silk and spun glass, in order that the silk may impart a durable character to the thread to enable it to withstand the chafing or friction incident to the operation of weaving or braiding. lVhere the thread is not to be woven or braided, however, I- do not consider it necessary to mix other fibers with the spun glass, as the latter has sufiicient strength and durability to withstand the operations of laying on by winding or in longitudinal strands. My improved insulation has the following advantages; Being of glass, it is not affected by ordinary acids, nor by gaseous fumes, nor by corrosive liquids. It cannot decay or deteriorate through lapse of time. It is noncorrosive. Itl is water-proof, not being affeeted by moisture or liquid, and is practically impervious thereto. It is non-infiammable, and is unaffected by heat until the latter approaches nearly or quite t0`the melting-point of glass. It is perfectly flexible, like any fibrous insulating-covering, and t-he material of which it is made possesses a higher resistance to the passage of electrical currents than any other insulating material.

For conductors which are not exposed'to moisture I contemplate the use of soluble glass, (silicate'of potash or soda,) to be applied as a varnish to the exterior of the insulating coating after the conductors are laid in place, so that they n longer require to be flexible.

My inventionlends itself readily to the application of colors to the insulating-coating, in order to distinguish wires of one kind or 4 belonging to one circuit from those of another kind or belonging to another circuit. y

In the multiplicity of wires laid in telegraphoffices, telephone-stations, public buildings, &c., the distinguishing of wires in this manner has gone largely into use and has become indispensable. To give the desired colors to the insulating-coating, I employ spun-glass laurents drawn from colored glass, these filaments being formed into threads or yarns in either solid or mixed colors. In the case of mixed colors I select yarns of two or more dierent colors yand weave or braid them on as the outer layer of insulation in such manner as to produce the desired combinatioh of colors in the form of a plaid or check. For insulations of solid color, as blue,lred, &c., I employ for the outer coating threads of colored spun glass, all of one color, and weave or braid them upon the wire. The colors thus obtained are as imperishable as the insulation itself and cannot fade or deaden like colors resulting from the use of paints or dyes. I have not undertaken herein to describe the manufacture of spun-glass filaments, as this I believe to be well known,as Well as the v spinning and Weavin g thereof into fabrics in imitation of silk. I will state, however, that, it is preferable for my purpose that the filaments should be very minute and that several of them shall be spun or twisted together during the process of drawing out, or subsequently while exposed to a high tempera.

ture. The twist should not be close, but` should be sufiicient to hold the filaments t0- gother and prevent their separation or the fiaking out of the thread or yarn during the operation of laying on. Two or more twisted threads thus made may be twisted together to form a compound thread or yarn.

I claim as my invention the following-defined novel features, substantially as hereinbefore specified, viz:

l. An insulating-covering for an electric conductor, consisting of a layer of filaments of spun glass laid longitudinally around the conductor and. an outer layer serving to bind said filaments against the conductor.

2. An insulating-covering for an electric conductor, consisting of a layer of filaments of spun glass surrounding said conductor IOO:

and a second layer of filaments of spun glass wound on spirally over the first layer.

3. An insulating-covering for an electric conductor, consisting of a layer of threads or' strands of glass filaments and filaments of silk or other textile fiber spun or twisted trgether, and the threads or strands thus formed wound, braided; or otherwise applied around the conductor. n

In witness whereof I have hereunto signed` my name in the-presence of two subscribinv.r

witnesses. l

THOMAS S. REED. Witnessesz-- l ARTHUR C. FRASER, Gannon ll. FRASER. i 

